Aqueous zinc-ion devices are considered promising candidates for energy storage due to their high safety,low cost and relatively high energy density.However,the dendrite growth,hydrogen evolution reaction(HER)and corr...Aqueous zinc-ion devices are considered promising candidates for energy storage due to their high safety,low cost and relatively high energy density.However,the dendrite growth,hydrogen evolution reaction(HER)and corrosion of the zinc anode significantly limit the development of Zn-ion devices.Here,an inexpensive poly(3,4-ethylenedioxythiophene)(PEDOT)protective layer was constructed in situ on the Zn surface using electropolymerization to suppress dendrite growth and side reactions,thereby enhancing the reversibility of Zn.Experimental and theoretical calculations revealed that this hydrophilic protective layer promotes the desolvation process of hydrated Zn^(2+)and facilitates the transport of zinc ions,thus improving the thermodynamic and kinetic properties of Zn^(2+)deposition and inhibiting interfacial side reactions.Consequently,the optimized PEDOT@Zn symmetric battery exhibited a cycling stability exceeding 1250 h at 0.5 mA·cm^(-2)and 0.25 mAh·cm^(-2),with a significantly reduced overpotential(from 91.8 to 35 mV).With the assistance of the PEDOT protective layer,the PEDOT@Zn//Cu battery maintained approximately 99.5%Coulombic efficiency after 450 cycles.Ex-situ scanning electron microscopy(SEM)and in situ optical microscopy characterizations further confirmed that the PEDOT protective layer can effectively suppress the growth of zinc dendrites.Additionally,the Zn-ion capacitors assembled by the PEDOT@Zn and activated carbon also demonstrated outstanding cycling stability.展开更多
基金the research fund of the National Natural Science Foundation of China(Nos.21902084,52222203 and 52073008)the Natural Science Foundation of Hubei Province(No.2022CFB354)the 111 Project of Hubei Province(No.2018-19-1)for financial support.
文摘Aqueous zinc-ion devices are considered promising candidates for energy storage due to their high safety,low cost and relatively high energy density.However,the dendrite growth,hydrogen evolution reaction(HER)and corrosion of the zinc anode significantly limit the development of Zn-ion devices.Here,an inexpensive poly(3,4-ethylenedioxythiophene)(PEDOT)protective layer was constructed in situ on the Zn surface using electropolymerization to suppress dendrite growth and side reactions,thereby enhancing the reversibility of Zn.Experimental and theoretical calculations revealed that this hydrophilic protective layer promotes the desolvation process of hydrated Zn^(2+)and facilitates the transport of zinc ions,thus improving the thermodynamic and kinetic properties of Zn^(2+)deposition and inhibiting interfacial side reactions.Consequently,the optimized PEDOT@Zn symmetric battery exhibited a cycling stability exceeding 1250 h at 0.5 mA·cm^(-2)and 0.25 mAh·cm^(-2),with a significantly reduced overpotential(from 91.8 to 35 mV).With the assistance of the PEDOT protective layer,the PEDOT@Zn//Cu battery maintained approximately 99.5%Coulombic efficiency after 450 cycles.Ex-situ scanning electron microscopy(SEM)and in situ optical microscopy characterizations further confirmed that the PEDOT protective layer can effectively suppress the growth of zinc dendrites.Additionally,the Zn-ion capacitors assembled by the PEDOT@Zn and activated carbon also demonstrated outstanding cycling stability.
